The present invention relates to a clutch arrangement for a motor vehicle transmission, for connecting a shaft to a rotational element, in particular to a freely moving wheel, which is mounted thereon, wherein the clutch arrangement has:                a sliding sleeve which is connected in a rotationally fixed fashion to the shaft and is mounted in an axially displaceable fashion on the shaft between a closed position and an open position and has a first sliding toothing;        a clutch element which is connected in a rotationally fixed fashion to the rotational element and has a second sliding toothing into which the first sliding toothing can be inserted axially in the closing direction in order to connect the rotational element to the shaft in the closed position; and        an actuator arrangement for axially sliding the sliding sleeve.        
In addition, the present invention relates to a method for engaging a gearspeed of a transmission, in particular of a motor vehicle transmission, specifically by axially sliding a sliding sleeve with respect to a clutch element, and a corresponding method for disengaging such a gearspeed.
Clutch arrangements of the type referred to above are generally known. They are generally used in what are referred to as manual shift transmissions, in automatic transmissions (ASG) and in double clutch transmissions (DKG). However, clutch arrangements of the aforesaid type can also be used for other connections between a shaft and a rotational element, for example between two shafts or the like.
The clutch element with the second sliding toothing can be formed separately from the rotational element and be fixedly connected to it. Alternatively it is also possible to form the clutch element in one piece with the rotational element.
In the case of the actuator arrangements, hydraulic actuators are known which hydraulically generate the force for axially sliding the sliding sleeve. In addition, what are referred to as electromechanical actuators are known in which the force of an electric motor is used to slide the sliding sleeve axially. In this context, a rotational/translational converter such as a shift drum is frequently used.
Document WO 86/05850 discloses an electromagnetic permanent magnet coupling for connecting two shafts of a machine tool etc., the equilibrium of forces of which in the closed state does not trigger a change of position even if there is a power failure but reduces the closing force of the clutch here in such a way that it can open in the case of inadmissible torques.
Document DE 100 07 847 A1 discloses an electromagnetic shifting device for a transmission in which a dog for connecting a shaft to a freely moving wheel can be slid axially by means of an electromagnetic device.
However, these known clutch arrangements are subject to relatively high wear or are not functionally expedient.